Container opening devices



Jan. 28, 1969 s. G. VON- STOCKER 3 CONTAINER OPENING DEVICES Filed July12, 1966 1 Sheet of 2 INVENTOR.

Mwaimm Jan. 28, 1969 s. G. VON STOCKER CONTAINER OPENING DEVICES SheetFiled July 12, 1966 Y. m MM W 2 EC 1 0 Wm .7 13 B T V fl United StatesPatent ABSTRACT OF THE DISCLOSURE This disclosure concerns an easy openend for pressurized containers having a removable portion defined by ascore line that has a multiplicity of relatively short segments ofincreased resistance to severance to prevent premature or uncontrollabletear strip severance caused by high internal pressures.

This invention relates generally to containers having integral openingdevices adapted to permit opening there of without the need for aseparate tool. More specifically it relates to a pressurized sealedcontainer adapted for opening with increased safety to the consumer.

In the conventional container embodying integral opening means, thecontainer is provided with a removable portion or tear strip defined byone or more scored lines and a pull-tab is afiixed within the tear stripto facilitate removal thereof. The more common systems have a rigid tabwhich functions as a lever to provide a mechanical advantage to theconsumer in effecting the initial score line fracture, which is thefirst of the two opening steps. After this, the second step, whichinvolves tearing away of the tear strip by continuing severance of thescore lines, is performed. The primary problem with increasing the easeof opening has resided in improving the ease with which initialseverance may be effected. One of the more practical approaches toimproving the initiation of score line fracture is that of scoringdeeper in the score line adjacent the tab fastening means. The limitupon the depth to which a panel may be scored while maintaining theintegrity of the package depends to a great extent upon the pressuredifferential to which the panel will be exposed. It is obvious that fora vacuum type container or pressurized beverage the scoring should notbe as deep as for a container having an internal pressure which isapproximately atmospheric.

A particular problem has been encountered with respect to packaging ofpressurized beverages such as beer or soft drinks. In these packages,while the internal pressure in effect provides an assist in theinitiation of score line fracture, it has frequently caused inadvertentfracture of the score line during storage. An additional and moreserious problem encountered during opening of the container has been theuncontrollable acceleration of tear strip severance caused by theescaping high internal pressures being exposed to the underside of thepull-tab and tear strip. This latter reaction has been known to forciblyremove the tear strip from the hand of the person opening the container,thereby exposing the individual to the risk of cut fingers as well asexposing him and others in close proximity to the hazard of a tear stripflying uncontrolled through the air. This hazard has generally beenreferred to as the rip off tendency.

It is an object of this invention to provide a sealed pressurizedcontainer having an end which incorporates an integral opening deviceand is adapted for ready safe opening by the consumer without exposureto the rip off tendency.

It is a further object of this invention to provide a pressurizedcontainer which is free from the rip off tendency and may be simply andeconomically manufactured Without substantial modification to existingcom- Inercial equipment.

It is another object of this invention to provide an integral openingdevice which eliminates the rip off tendency while retaining ease ofopening characteristics.

It is yet another object to provide such a pressurized container havingimproved resistance to accidental opening.

These and other objects will be more fully understood and appreciatedfrom the following detailed description of the invention, on referenceto the illustrations appended hereto, in which: 7

FIGURE 1 is a fragmentary perspective of a sealed container adapted foruse with this invention;

FIGURE 2 illustrates asectional view of a container of the typeillustrated in FIGURE 1, immediately after score line severance has beeninitiated;

' FIGURE 3 is a plan view of a container end of this invention, with thepull-tab not shown for convenience of illustration;

FIGURE 4 is a fragmentary sectional view through 44 of FIGURE 3;

FIGURE 5 is a plan view of a modified form of container end within theinvention, with the pull-tab not shown for convenience of illustration;

FIGURE 6 is a fragmentary sectional representation of a differentialscoring concept adapted for use with this invention; and

FIGURE 7 illustrates another embodiment of the invention'with thepull-tab removed for convenience of illustration.

Turning more specifically to the drawings, as is shown in FIGURE 1, acontainer 1 has an end wall 2 provided with a removable portion or tearstrip 3 which is defined by scored line or lines 4. Within the tearstrip 3 at one end thereof is affixed a pull-tab 5 which is secured tothe tear strip 3 by any conventional fastening means 6, such as anintegral rivet, for example. The tab 5 is reinforced by one or more ribs7 in order to facilitate its functioning as a rigid lever. In effectinginitial severance of the scored line 4, the consumer grasps grippingportion 8 and raises it, thereby effecting engagement of fulcrum 9 withthe end wall or panel 2. Continued upward rotation results in employmentof the mechanical advantage of the lever tab to effect initial fractureof the score line 4.

FIGURE 2 illustrates the position of the pull-tab 5 at the instantimmediately after initial severance. At this instant a relatively smallaperture A is created. The ripoff tendency arises from the gas at highinternal pressure attempting to instantaneously exhaust through theaperture which is inadequate in size for this purpose. What tend tooccur, therefore, is that the end yields at its points of leastresistance, which are the scored lines, and the uncontrolledacceleration of scored line severance occurs. As was stated above, thismay result in cut fingers as well as the hazard of a tear strip flyinguncontrolled through the air.

An additional problem experienced with pressurized containers havingintegral opening devices is that of preventing accidental severance ofthe scored lines by the internal pressure during storage. Althoughefforts have been made to provide an adequate score line residual toresist the pressure, the primary desire for increased ease of openinghas prevented the use of scoring sufliciently shallow to effectivelyeliminate leakers."

This invention contemplates an effective solution to the aforementionedproblems by providing a multiplicty of sectors of increased resistanceto severance on the scored lines. These sectors of increased resistancewill prevent rapid and uncontrolled acceleration of the score lineseverance and will thereby prevent rip-off. Also, these sectors will actto reinforce the end panel and resist accidental score line severance.The foregoing is readily accomplished by the sectors of increasedresistance, while not interfering with the more difiicult stage ofopening, i.e., the initiation of score line severance. The second stageof Opening, the tearing away of the tear strip by continuing thepreviously initiated score line severance, is effectively controlled andaccidental migration of the score rline severance is prevented. Thislatter stage of opening has not proved difficult for the consumer andtherefore the slight increase in the amount of applied force required tocomplete tear strip removal, does not result in any meaningfuldifference in tear strip removal characteristics and is entirelytolerable.

As the preferred form of this invention relates to pressurizedcontainers for flowable materials, such as beer or carbonated beverages,for example, the tear strip 3 will generally be elongated to provide anelongated orifice with adequate opening for pouring and will cover aminor portion of the panel. For ease of pouring, this elongated tearstrip will preferably, but not necessarily, be disposed in a generallyradial direction. The term innermost end as used herein will refergenerally to the area which contains the tab securing means and may begeometrically defined as being separated from the remainder of the tearstrip by a line perpendicular to the tear strip centerline near thecenter thereof and intersecting the scored line at two points. In FIGURE5, the innermost end 13 is defined by line 19 which is perpendicular tocenterline 20.

In the embodiment of the invention shown in FIG- URES 3 and 4 thecontainer end has a multiplicity of segments of increased resistance inthe form of score line portions which are scored to different depthsthereby providing a path of varied resistance which undulates in adirection substantially perpendicular to the container end panel. Whileit will be appreciated that the resistance to severance is actuallyprovided by the residual metal remaining after scoring, for convenienceof discussion, reference will be made to depth of score. For sheet ofsubstantially uniform thickness, such as is generally employed incontainers, the thickness of the residual metal will, of course, beequal to the difference between the original thickness and the depth ofscore. Also, it will be apprciated that these idealized dimensionsactually represent a depth plus or minus the tooling and metal thicknesstolerances.

In FIGURE 4, the original metal thickness is a-d and the normal scoringdepth is a-c. Interrupting the score line depth 11-0 and alternatingtherewith are a plurality of score line segments which are scored to adepth a-b. The effect of these sectors is to require periodic severanceof the increased residual left by scoring to a shallower depth a-b.While the exemplary FIGURE 4 illustrates only one scoring depth (a-b)deviating fro-m the regular depth (a-c), it will be appreciated thatwhere desired, two or more different scoring depths other than theregular or standard depth (a-c) may be employed in order to provide agradation of resistances. In lieu of or in addition to such variations,the segments of regular depth score may also be varied to provide evengreater control. This is merely a matter of choice. What is essential isthat there be a plurality of sectors of one or more scoring depthsdisposed on the score line in alternating position with a plurality ofsectors of different scoring depths. There is no critical length for anyof the sectors, nor need they be of equal length. It is, however,desirable for them to be of relatively short length in order to providerefined control of the resistance to severance. In FIGURE 3, the end 2has a multiplicity of segments 11 scored to the conventional depth and amultiplicity of segments 12 which are scored to one or more depths whichare more shallow than the depth of segments 11 and are alternatelyinterspaced between the segments 11. It is noted that the segmentscontinue along substantially the entire scored line 4. While it is notessential, it is desirable for purposes of avoidance of accidentalrupture of the score line by the pressure differential across the panel,that these alternating segments continue over a major portion of thescore line. Where the regular or deepest score is sufficiently shallowthat accidental fracture or leakage is not of major concern, a lesserportion of the score line may be segmented and avoidance of the rip offtendency will still be obtained. Even where accidental fracture is not aproblem and the sole purpose for placing segments of varying resistanceon the score line is avoidance of the rip off hazard, it is generallydesirable to provide these segments over a major portion of theinnermost end 13, i.e., the end of the tear strip 3 to which thepull-tab 5 is affixed.

It will be appreciated that the flexibility of the system permits veryfine, precise control of the opening properties and permits panel designcorresponding precisely to the contemplated pressure differential acrossthe panel. In addition to adjusting the score depths of segments 11, 12,the lengths of the respective segments may be varied. It is notnecessary that the segments 11 be of equal length to the segments 12,nor is it necessary that all of the segments 12 or segments 11 be ofequal length, although all of the segments should be of relatively shortlengths. The end shown in FIGURE 5 has a plurality of segments at theinnermost end 13 of tear strip 3 which are shorter than the segments atthe outermost end 14 of the tear strip.

It will be further appreciated that the end is adapted to be made withsubstantially the same equipment presently used in the commercialmanufacture of such ends, with only minor modifications to the toolingbeing required. It is also compatible with improvements presently beingmade to existing forms of container ends. As was shown in Henchert US.Patent No. 3,151,766, the ease of effecting initial score line fracture,i.e., the first opening step, may be improved by scoring the innermostend 13 of tab 5 more deeply than the remainder of the scoring. Thisprinciple may be incorporated into our end by scoring the segments 11,12 deeper in the innermost end 13 than at the outermost end 14. Forsimplicity, it is preferable, but not essential, that the depth ofsegments 11 on the innermost end 13 differ from the depth of segments 11in the outermost portions 14 by substantially the same amount as thecorresponding differences between similarly disposed segments 12. Aprofile of such scoring is illustrated in FIGURE 6 with the solid line15 representing the depth of the scoring at the innermost end 13 anddotted line 16 representing the depth of the scoring on the remainingportion of the score line.

Additional simplicity is obtained with slightly reduced control byscoring all segments 11 to the same depth and all segments 12 to thesame depth, but less than the depth of segments 11.

Turning to another embodiment of the invention, FIG- URE 7 shows anothertype of container end which has segments of increased resistance tofracture 17. These segments consist of score line portions 18 whichundulate in a direction substantially coplanar with the container endpanel. These abrupt changes of direction provide increased resistance toscore line severance in order to prevent uncontrolled severance of thescored lines and thereby eliminate the hazard of the rip off tendency.These segments may preferably extend over a major portion of theinnermost end 13 of the tear strip 3. It will be obvious to thoseskilled in the art that there may be instances where it would bedesirable to combine this embodiment with the varying score lineembodiment in a single end adapted for use with a pressurized container.

Throughout the discussion the terms score lines and scored line(s) havebeen employed interchangeably, as the principle of the invention isequally applicable regardless of whether the tear strip is considered asbeing bounded and defined by one score line or a number of them.

Whereas particular embodiments of the invention have been describedabove for purposes of illustration, it will be evident to those skilledin the art that numerous variations of the details may be made withoutdeparting from the invention as defined in the appended claims.

I claim:

1. A container end for pressurized sealed containers, comprising,

a panel portion having an elongated removable portion defined by atleast one scored line,

a pull-tab aflixed to one end of said removable portion, and

said scored line containing a multiplicity of relatively short segmentsof increased resistance to severance.

2. A pressurized sealed container comprising in combination thecontainer end of claim 1 wherein said segments of increased resistanceare undulating score line portions, and

a container body sealingly joined to said end.

3. The pressurized sealed container of claim 2 wherein said portionsundulate in a path which is substantially cplanar with the plane of saidcontainer end panel.

4. The pressurized sealed container of claim 2 wherein said portionsundulate in a path which is substantially perpendicular to the plane ofsaid container end panel.

5. The pressurized sealed container of claim 4 wherein each saidsegments are of relatively short length and are adjacent segments ofrelatively short length scored to a dilferent depth.

6. The pressurized sealed container of claim 5 wherein alternatesegments are scored to substantially equal depths.

7. The pressurized sealed container of claim 5 wherein said relativelyshort score line segments are disposed over a major portion of saidscore line.

8. The pressurized sealed container of claim 5 wherein all of saidsegments are of substantially equal length.

9. The pressurized sealed container of claim 5 wherein said elongatedremovable portion extends substantially radially over a minor portion ofsaid container end panel and said relatively short score line segmentsare disposed over substantially all of said score line.

10. The pressurized sealed container of claim 6 wherein said relativelyshort score line segments which are of substantially equal depths are ofsubstantially equal length.

11. The pressurized sealed container of claim 6 wherein said alternatesegments in the innermost end of said elongated removable portion arescored deeper than the respective corresponding alternate segments inthe remainder of said removable portion.

12. The pressurized sealed container of claim 11 wherein the increase indepth of score in each of said alternate segments in the innermost endof said elongated removable portion with respect to the depth of scorein each of the respective corresponding alternate segments in theremainder of said removable portion is substantially equal.

References Cited UNITED STATES PATENTS 3,221,923 12/1965 Bozek 220--543,291,336 12/1966 Fraze 220-54 GEORGE T. HALL, Primary Examiner.

